2024 AIChE Annual Meeting
Separating Stable Chloride Isotopes for Molten Salt Reactors
37Cl- is the preferred isotope for thermal reactors, as chlorides are only candidates for secondary cooling loops. It is also required for molten salt reactors (MSRs), which generate electricity that can be used. Since 37Cl- only has a 24% abundancy for all Cl isotopes, the US supply is currently limited, and cannot be as widely utilized. Therefore, the goal of this project is to take a
compound that is not highly limited, such as HCl, and extract the 37Cl- isotope from it. As of right now, the isolation of the 37Cl- isotope has been studied through anion exchange resins, but
unfortunately there are handling issues, as well as the lack of cost and maintenance feasibility. Therefore, liquid-liquid extraction (LLE) is being studied as an alternative process. LLE is a
process in which compounds are separated into an organic and aqueous phase, which can then be easily separated. When chloride ions interact with trioctylamine (TOA), the 37Cl- tends to be
attracted to the TOA, whereas 35Cl- tends to be repulsed, remaining in its original solvent. The 37Cl- then interacts with NaOH, AgNo3, and 1-iodobutane through a series of separation and
filtration processes in order to isolate the 37Cl- into 1-chlorobutane. The 1-chlorobutane is then analyzed using a GC/MS, as this provides the makeup of the compound, as well as the amount of
each Cl isotope that was extracted. Once this process has been proven successful, the next goal is to optimize it through different solvent ratios, temperatures, and process times, to achieve the
maximum amount of 37Cl- possible. This optimization is done through the program Aspen Plus V8.8, using the ELECNRTL methodology as it is best suited for aqueous and mixed solvent
applications.
compound that is not highly limited, such as HCl, and extract the 37Cl- isotope from it. As of right now, the isolation of the 37Cl- isotope has been studied through anion exchange resins, but
unfortunately there are handling issues, as well as the lack of cost and maintenance feasibility. Therefore, liquid-liquid extraction (LLE) is being studied as an alternative process. LLE is a
process in which compounds are separated into an organic and aqueous phase, which can then be easily separated. When chloride ions interact with trioctylamine (TOA), the 37Cl- tends to be
attracted to the TOA, whereas 35Cl- tends to be repulsed, remaining in its original solvent. The 37Cl- then interacts with NaOH, AgNo3, and 1-iodobutane through a series of separation and
filtration processes in order to isolate the 37Cl- into 1-chlorobutane. The 1-chlorobutane is then analyzed using a GC/MS, as this provides the makeup of the compound, as well as the amount of
each Cl isotope that was extracted. Once this process has been proven successful, the next goal is to optimize it through different solvent ratios, temperatures, and process times, to achieve the
maximum amount of 37Cl- possible. This optimization is done through the program Aspen Plus V8.8, using the ELECNRTL methodology as it is best suited for aqueous and mixed solvent
applications.